China's largest fixed-line phone carrier has denied it hijacked worldwide Internet traffic this past April following a U.S. government report that said the company had redirected network routes through Chinese servers.

China Telecom rejected the claims in an email statement, but offered no further comment.

A report to the U.S. Congress published on Wednesday claims that for 18 minutes on April 8, China Telecom rerouted 15 percent of the Internet's traffic through Chinese servers. The traffic affected U.S. government and military websites, said the U.S.-China Economic and Security Review Commission in the report.

Computer security researchers cannot say if the act was intentional, the report said. But such hijacking of Internet traffic could enable the surveillance of specific users or sites, or it could have been used to conceal one targeted cyberattack, the report adds.

According to the report, what caused China Telecom to reroute Internet traffic, however, originated with a smaller Internet service provider called IDC China Telecommunication, which could not be reached for comment.

The incident could have been an accident that stems from a weakness of the Border Gateway Protocol (BGP), which is used to help route traffic and connect the Internet together.

BGP data is sent from small service providers like IDC China Telecommunication and then shared with larger providers. Small providers generally direct Internet traffic to about 30 routes. For some reason, on April 8 IDC China Telecommunication began directing to tens of thousands of networks. The bad information was then accepted by larger Internet providers like China Telecom, which then propagated the data.

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